Terry Zwigoff’s Bad Santa is a no-holds-barred misanthropic black comedy that takes every cherished cliché of Christmas movies and stands them on their head. Crass, crude, vulgar, and often side-splittingly hilarious, this is a movie that makes no excuses for itself or even attempts to find redemption for its slovenly alcoholic antihero. The one binding characteristic of virtually all Christmas movies, from It’s a Wonderful Life (1946) to Dr. Seuss’ How the Grinch Stole Christmas (2000)—that the central character learns an important life lesson—is here reduced to a kid learning to kick a bigger kid in the balls when he’s picked on. How’s that for Christmas spirit?

Billy Bob Thornton stars as the title character, a worn-down, alcoholic safecracker aptly named Willie T. Sokes. Sokes has had it up to here with life (one of the first lines in his voice-over narration is “Nothing has sucked ass worse than this”), and he spends most of his time drowning it all out with booze and his own twisted disgust with virtually everything and everyone. This doesn’t mesh very well with the scheme he’s been running for the past eight years with his partner, Marcus (Tony Cox), a dwarf who makes up for his diminutive size with plenty of attitude. Working each Christmas season in a different city as a department store Santa and his assistant elf, Sokes and Marcus case the store for a month, then hide out after lockup and break into the safe. Unfortunately for both of them, this means they have to show up for work everyday and put up with kids of all shapes and sizes.

One kid Sokes ends up spending a lot of time with is a chubby little snot-nosed toad who is usually just referred to as “the kid” (Brett Kelly). Although the kid’s name is eventually made known, it’s done so in such a hilarious revelation that I won’t kill it by saying what it is here. Sokes ends up staying at the kid’s house because both of his parents are gone (his mom is dead and his dad, a corporate accountant, is in jail) and the only person to watch after him is his cadaverous grandmother (Cloris Leachman). Sokes isn’t worried at all about the kid’s well-being; he just sees a glorious opportunity to shack up in a nice house and drive a BMW to work every morning.

The screenplay, penned by John Requa and Glenn Ficarra (Cats & Dogs), seems to be setting up a potentially feel-good story about how a lonely kid redeems a bitter would-be father figure, but the movie’s central pleasure is watching how that set-up is constantly undermined again and again. First of all, Sokes is simply beyond redemption. He is so foul, so misanthropic, so outright pathetic that it would take much more than a tenuous relationship with a lonely kid to make him anything less than dismal (although, to be fair, as a character he grows on you if only because he’s so wretchedly consistent in his behavior).

Even more effective is the kid himself, who goes against every convention of the “cute movie kid” imaginable. For starters, he’s not chubby-cute, but rather he’s disconcertingly obese. But, more than that, he’s impossibly blank. For most of the movie, Sokes fires insult after insult at him, each of which he absorbs without ever registering a sense of hurt. It’s as if he doesn’t even hear what Sokes is saying. He also displays several annoying tendencies, such as asking one inane rapid-fire questions after another and persisting in doing little good deeds for Sokes that clearly irritate him. Yet, much like Sokes, the kid grows on you despite the fact that everything about him makes your skin crawl.

Director Terry Zwigoff has mined this territory before. He first gained recognition for his marvelous documentary Crumb (1994) about the misanthropic underground cartoonist Robert Crumb and his even more twisted family members. Zwigoff’s first foray into feature films was 2001’s Ghost World, about a pair of teenage girls on the cusp of adulthood trying to find their identities without selling out to the commodified world they can’t stand. In each of these films and in Bad Santa, Zwigoff manages a delicate balancing act by giving us characters that are defined by conventionally loathsome characteristics and somehow making them not only watchable, but compelling.

Willie Soke’s alcohol-fueled descent into personal self-destruction is at time hilarious and at times sad, and it is a testament to both Zwigoff’s direction and Thornton’s superbly nasty performance that he never feels overplayed. As Marcus, Tony Cox sometimes overworks his inner anger a bit, although this is balanced somewhat by Bernie Mac’s underplaying his role as a department store security chief and the late John Ritter’s perfectly tuned antsy performance as the store’s uptight manager.

It is true that Bad Santa has what might described as a “happy ending.” That is, not everyone dies, although there is a wild police chase and one character gets shot in the back eight times while trying desperately to deliver a present (the fact that it is the wrong present undermines any potential sentimentality). Yet, after spending time with all these odious characters and developing genuine affection for them (even if you wouldn’t want to be a room with them in real life), it’s only right that things turn out as they do. As John Waters famously said, there’s good bad taste and bad bad taste, and Bad Santa excels in the former. It’s good bad taste par excellence.